‘Rat Urine Infections’ Are Alarmingly Surging in NYC

The rates of life-threatening leptospirosis, dubbed as “rat urine infection,” reached an all-time high in New York City, health officials warn.

Twenty-four cases of leptospirosis were reported in NYC in 2023 — the highest number in the last two decades, according to the NYC Department of Health and Mental Hygiene.

This is a major increase from the average of 15 cases a year reported from 2021 to 2023 and three cases annually from 2001 to 2020.

A further rise in cases may occur in 2024, as six people have been infected with leptospirosis since the beginning of the year.

Leptospirosis is a bacterial disease caused by bacteria of the genus Leptospira. Due to symptoms like high fever, headache, and gastrointestinal issues, the disease is often mistaken for other conditions. If left untreated, the “rat urine infection” can cause severe complications and even death.

How does leptospirosis spread?

Leptospirosis transmission occurs through direct contact with the urine of infected rats or urine-contaminated water, soil, or food. The bacteria enter the body through open wounds or mucous membranes.

In NYC, infected individuals have a history of residential or occupational exposure to rat urine or environments, including soil and water. Infections were also linked to exposure to materials contaminated with rat urine, such as handling trash bags or bins containing food waste.

Person-to-person transmission is rare.

Ninety-eight cases of leptospirosis have been reported since 2001, mostly from the Bronx, where 37 people were infected, followed by Brooklyn, Manhattan, Queens, and Staten Island.

The infected individuals experienced failure of kidneys and liver and lung problems. Six people died of the disease.

What are the symptoms of leptospirosis?

Leptospirosis has a wide spectrum of symptoms, which include high fever, headache, chills, muscle aches, vomiting, jaundice, red eyes, abdominal pain, diarrhea, and rash.

The illness lasts from a few days to three weeks or longer. Without treatment with antibiotics such as doxycycline or penicillin, recovery may take several months.

The disease can lead to severe complications, such as kidney damage, meningitis, which is the inflammation of the membrane around the brain and spinal cord, liver failure, respiratory distress, and even death.

Should we worry about leptospirosis?

Leptospira bacteria can die within minutes in dry heat or freezing temperatures. However, excessive rain and unseasonably warm temperatures increase the bacteria’s chance of survival. Last year, half of the cases were reported during June and October, which were warmer and wetter than usual.

This adds leptospirosis to a long list of health risks associated with climate change, such as respiratory and heart conditions and vector-borne diseases.

Shaun Abrew, a NYC council member, called rats a public health crisis.

“It’s why we need rat contraceptives & citywide containerization—to reduce rats, remove bags, and protect our sanitation workers,” Abrew wrote on X, a social network.

Eric Adams, the mayor of NYC, announced the war on rats, but victories have been modest thus far. A recent analysis by the New York Post found that rodent complaints rose by nearly 8% in the city since Adams took office.

A new bill was introduced in the City’s Council that would require deploying salty pellets to sterilize male and female rats in infested areas of the city as part of a pilot program. Proponents say it is a more humane method than rat poison.